Sample Handler Research Articles

B-008 An Evaluation of the Analytical Performance of the New Beckman Coulter DxC 500i Clinical Analyzer

Abstract Background The DxC 500i Clinical Analyzer* is Beckman Coulter’s latest integrated Clinical Chemistry and Immunoassay analyzer. It provides reliability, scalability, and workflow efficiency via a flexible independent maintenance mode, increased uptime, and a dynamic sample handler to optimize sample management. Standard Beckman Coulter Chemistry and Immunoassay consumables and reagents ensure network standardization and commutability. The purpose of this study was to evaluate the analytical performance of the new DxC 500i analyzer and to compare the performance against the Beckman Coulter stand-alone Clinical Chemistry and Immunoassay analyzers on the market. Methods To assess performance over a range of assay methodologies, several DxC 500i Beckman Coulter Immunoassays and Chemistry assays were evaluated. Precision was assessed using human samples following CLSI EP05-A3 guidelines. Linear range was assessed following CLSI EP06-A guidelines. Method Comparison and Bias Estimation studies compared the DxC 500i Clinical Analyzer against the Access 2 Immunoassay System, the AU480 and the DxC 700 AU Clinical Chemistry analyzers, following CLSI EP09c-ED3 guidelines. To investigate carryover potential as samples are processed across the integrated system, a carryover study was designed. This focused on evaluating potential sample-to-sample carryover caused by the AU sample probe and its effects on immunoassay samples during reflex scenarios. Results DxC 500i Chemistry results: Glucose Serum (OSR6x21) Assessments of repeatability and within laboratory precision at multiple critical analyte concentrations showed total imprecision of <3% and within-run imprecision of <3%. The Glucose serum assay demonstrated acceptable linearity throughout the 10-800 mg/dL analytical measuring range. Method comparison studies compared the DxC 500i analyzer against the AU480 and DxC 700 AU systems. A Weighted Deming regression of serum patient samples (n>100 measured across the analytical range) yielded a 0.986 slope, 0.227 mg/dL intercept, and R=0.9999 correlation coefficient against the DxC 700 AU and a 0.995 slope, 0.356 mg/dL intercept, and R=0.9999 correlation coefficient against the AU480. DxC 500i Immunoassay results: Cortisol (33600) Beckman Coutler’s Cortisol assay exhibited total imprecision of <12%CV at <5 μg/dL or <10CV% at ≥5 μg/dL for serum. The Cortisol assay demonstrated acceptable linearity throughout the 0.4-60 μg/dL analytical measuring range. A method comparison study compared the DxC 500i against the Access 2 system. A Weighted Deming regression of serum patient samples (n>100 measured across the analytical range) yielded a 0.9785 slope, 0.2764 μg/dL intercept, and R=0.9932 correlation coefficient. DxC 500i Carryover Assessment The Total βhCG (5th IS) assay was used to evaluate the potential of chemistry analyzer to immunoassay analyzer sample carryover. The study used High hCG serum samples (>1,000,000 mIU/mL) and Low hCG serum samples (4-6 mIU/mL). The DxC 500i exhibited a cumulative carryover of ≤2 parts per million (PPM) for serum. Conclusions These studies demonstrate excellent analytical performance for the new Beckman Coulter DxC 500i Clinical Analyzer* and confirm comparable performance to current Beckman Coulter standalone Clinical Chemistry and Immunoassay analyzers on the market. *Pending clearance by the United States Food and Drug Administration; not yet available for in vitro diagnostic use in the U.S. Product availability and regulatory status depends on country registration per applicable regulations.

Multi-axis electromagnetic sample handler for multi-view imaging and point-spread function deconvolution of organoids

Multi-axis electromagnetic sample handler for multi-view imaging and point-spread function deconvolution of organoids

Multi-axis electromagnetic sample handler for live imaging of organoid structures and dynamics.

Organoids are a flexible experimental model to explore countless human conditions. They can emulate essential physiological and pathological functions of an in vivo system. Acquiring three-dimensional (3D) images is critical but challenging in live organoid-based studies due to the complex structure of these samples. Imaging quality worsens in deeper microscopic planes because of light scattering. Furthermore, the imaging system introduces an unavoidable image distortion, the point spread function (PSF). Current methods to decrease these issues are often expensive, highly complex, limited to specific usage, or unsuitable for live organoid experiments. Increasing the freedom of movement within the microscope field of view for imaging organoid samples can minimize the light depth penetration limitation and the PSF distortion. To address this, we are developing an electromagnetic sample handler that will enable multi-axis rotation for high-resolution microscopy. We have also developed a complementary image reconstruction algorithm. Our initial results are promising, demonstrating that this sample handler provides a higher freedom of movement, can be integrated into existing imaging platforms, and has helped enable enhanced visualization of organoid structures.

X‐ray Solution Scattering Studies at the Life Sciences X‐ray Scattering (LiX) Beamline

Solution small angle X-ray scattering (SAXS) is a method to characterize the behavior of particles such as proteins and protein complexes in solution. Information about particle size and shape as well as oligomeric state can be determined from the 1D scattering profiles. The life sciences X-ray scattering (LiX) beamline at NSLSII operates in two modes: I) X-ray imaging and II) solution scattering (BioSAXS). Here, we discuss the types of BioSAXS measurements performed, automation, remote collection, data processing and examples of user data. Static SAXS measurements are high throughput and managed with a sample handler, with room for up to 360 samples organized into 18-well holders. Each holder contains two rows that are connected to separate channels of a flow cell that aligns with the X-ray beam. As the sample flows into the channel and is illuminated by the X-ray beam, small angle (SAXS) and wide angle (WAXS) data is collected simultaneously on two detectors with a q-range of 0.006Å-1 to 3.2 Å-1. This type of measurement requires pure, monodisperse sample and for the case when mixed populations exist, such as dimers and monomers, static SAXS will produce poor data quality. Therefore, size exclusion chromatography coupled with SAXS (SEC-SAXS) should be considered to separate each species. At LiX, the center flow channel is connected to an HPLC system, which allows for seamless integration of SEC-SAXS into the workflow without having to make changes to the beamline hardware setup. Once data is collected, it is packaged into HDF5 format and automatically processed. Data is transferred to users via Globus. We now offer remote collection and users can ship samples in holders or 96-well plates. Samples sent in plates are loaded into an Opentrons liquid handling system and transferred into sample holders. Additionally, having the Opentrons allow us to manipulate sample conditions through dilution, mixing and/or screening right before measurement.

A high-flux automated laboratory small-angle X-ray scattering instrument optimized for solution scattering

A commercially available small-angle X-ray scattering (SAXS) NanoSTAR instrument (Bruker AXS) with a liquid-metal-jet source (Excillum) has been optimized for solution scattering and installed at iNANO at Aarhus University. The instrument (named HyperSAXS) employs long high-quality parabolic Montel multilayer optics (Incoatec) and a novel compact scatterless pinhole slit with Ge edges, which was designed and built at Aarhus University. The combination of the powerful source and optimized geometry gives an integrated X-ray intensity close to 109 photons s−1 for a standard range of scattering vector moduli q = 0.0098–0.425 Å−1, where q = (4πsinθ)/λ and λ is the Ga Kα wavelength of 1.34 Å. The high intensity of the instrument makes it possible to measure dilute samples of, for example, protein or surfactant with concentrations of 1 mg ml−1 in a few minutes. A flow-through cell, built at Aarhus University, in combination with an automated sample handler has been installed on the instrument. The sample handler is based on the commercial Gilson GX-271 injection system (Biolab), which also allows samples to be stored under thermostatted conditions. The sample handler inserts and removes samples, and also cleans and dries the sample cell between measurements. The minimum volume of the flow-through capillary is about 20 µl. The high intensity additionally allows time-resolved measurements to be performed with a temporal resolution of seconds. For this purpose a stopped-flow apparatus, (SFM-3000, Bio-Logic) was connected to the flow-through cell by high-performance liquid chromatography tubing. This configuration was chosen as it allows vacuum around the sample cell and thus maintains a low background. The instrument can readily be converted into a low-q setup with a q range of 0.0049–0.34 Å−1 and an X-ray intensity of about 5 × 107 photons s−1.

Solution scattering at the Life Science X-ray Scattering (LiX) beamline.

This work reports the instrumentation and software implementation at the Life Science X-ray Scattering (LiX) beamline at NSLS-II in support of biomolecular solution scattering. For automated static measurements, samples are stored in PCR tubes and grouped in 18-position sample holders. Unattended operations are enabled using a six-axis robot that exchanges sample holders between a storage box and a sample handler, transporting samples from the PCR tubes to the X-ray beam for scattering measurements. The storage box has a capacity of 20 sample holders. At full capacity, the measurements on all samples last for ∼9 h. For in-line size-exclusion chromatography, the beamline-control software coordinates with a commercial high-performance liquid chromatography (HPLC) system to measure multiple samples in batch mode. The beamline can switch between static and HPLC measurements instantaneously. In all measurements, the scattering data span a wide q-range of typically 0.006-3.2 Å-1. Functionalities in the Python package py4xs have been developed to support automated data processing, including azimuthal averaging, merging data from multiple detectors, buffer scattering subtraction, data storage in HDF5 format and exporting the final data in a three-column text format that is acceptable by most data analysis tools. These functionalities have been integrated into graphical user interfaces that run in Jupyter notebooks, with hooks for external data analysis software.

Validation and Implementation of the Roche FLOW System in a Large Routine Molecular Diagnostic Laboratory

Background - The PHE Public Health Laboratory, Birmingham at Heartlands hospital has an annual turn-over in excess of 750,000 specimens, 41,000 of which are processed using real-time PCR in the molecular section. In 2017, due to the age of existing instrumentation, the laboratory began a programme of replacement. Methods - During 2017-19 the entire molecular service was replaced with a new high-throughput automated Roche FLOW system, consisting of a primary sample handler (PSU), two MagNA Pure 96 instruments, a PCR set-up unit (PSU), three 384-well LightCycler 480 II instruments and overarching FLOW software responsible for automated data handling, specimen tracking and workflow between the instruments. Results - The bulk of the in-house developed assay repertoire, representing 34 viral, bacterial and fungal targets was re-optimised in 19 multiplexes. These were fully validated against existing molecular tests and were introduced into routine diagnostic service in June 2018. The FLOW software was successfully interfaced with the LIMS system, allowing rapid two-way communication of test requests and results. Over the following ten months, the service was expanded with an additional seven targets. The new system and assays were audited by UKAS in April 2019 and achieved accreditation to ISO:15189:2012 in August 2019. Conclusion – The Roche FLOW system was successfully validated and introduced into routine diagnostic service and now offers significant improvements in assay performance, sample throughput and turnaround time. Details of the validation process, post-implementation modifications, trouble-shooting and lessons learnt will be of value to other diagnostic laboratories considering the introduction of this technology.

Development of a 0.5 T magnetic‐core alternating‐field demagnetizer

AbstractWe have constructed an alternating‐field (AF) demagnetizer with a magnetic core in a passively air‐cooled coil that can routinely operate at fields up to 0.5 T, almost 3 times higher than we could attain before in our commercial instrument. The field is powered by a commercial 1 kW power amplifier and is transverse to the bore, uniform to ±2% over a 25 mm paleomagnetic sample, and compatible with our existing sample handler for automated demagnetization and measurement. Even harmonics are ≤1 ppm of the fundamental and so generate negligible anhysteretic remanence. The much higher peak alternating field, 2 and 5 times that commonly available in air‐core solenoidal and Helmhotz coil configurations, respectively, enables successful AF demagnetization of many samples that could not be completely demagnetized with commercially available equipment. This capability is especially useful for high‐coercivity sedimentary and igneous rocks and extraterrestrial materials that contain magnetic minerals that alter during thermal demagnetization. In addition to the benefits, this instrument brings to our own research, a much broader potential impact is that it could replace the transverse coils of most automated AF demagnetization systems in use today, whether for discrete or continuous U‐channel measurements, which are commonly limited to peak fields of ∼100 mT. Manual and tumbling demagnetizers would benefit as well by the ∼2 times increase in maximum field over those that can be attained by commercial solenoidal coils. Furthermore, we expect that it and similarly designed magnetic‐core instruments will be capable of attaining even higher fields, of order 1 T.

Advances in artificial olfaction: sensors and applications.

The artificial olfaction, based on electronic systems (electronic noses), includes three basic functions that operate on an odorant: a sample handler, an array of gas sensors, and a signal-processing method. The response of these artificial systems can be the identity of the odorant, an estimate concentration of the odorant, or characteristic properties of the odour as might be perceived by a human. These electronic noses are bio inspired instruments that mimic the sense of smell. The complexity of most odorants makes characterisation difficult with conventional analysis techniques, such as gas chromatography. Sensory analysis by a panel of experts is a costly process since it requires trained people who can work for only relatively short periods of time. The electronic noses are easy to build, provide short analysis times, in real time and on-line, and show high sensitivity and selectivity to the tested odorants. These systems are non-destructive techniques used to characterise odorants in diverse applications linked with the quality of life such as: control of foods, environmental quality, citizen security or clinical diagnostics. However, there is much research still to be done especially with regard to new materials and sensors technology, data processing, interpretation and validation of results. This work examines the main features of modern electronic noses and their most important applications in the environmental, and security fields. The above mentioned main components of an electronic nose (sample handling system, more advanced materials and methods for sensing, and data processing system) are described. Finally, some interesting remarks concerning the strengths and weaknesses of electronic noses in the different applications are also mentioned.

QTREDS: a Ruby on Rails-based platform for omics laboratories

BackgroundIn recent years, the experimental aspects of the laboratory activities have been growing in complexity in terms of amount and diversity of data produced, equipment used, of computer-based workflows needed to process and analyze the raw data generated. To enhance the level of quality control over the laboratory activities and efficiently handle the large amounts of data produced, a Laboratory Management Information System (LIMS) is highly-recommended. A LIMS is a complex software platform that helps researchers to have a complete knowledge of the laboratory activities at each step encouraging them to adopt good laboratory practices.ResultsWe have designed and implemented Quality and TRacEability Data System - QTREDS, a software platform born to address the specific needs of the CRS4 Sequencing and Genotyping Platform (CSGP). The system written in the Ruby programming language and developed using the Rails framework is based on four main functional blocks: a sample handler, a workflow generator, an inventory management system and a user management system. The wizard-based sample handler allows to manage one or multiple samples at a time, tracking the path of each sample and providing a full chain of custody. The workflow generator encapsulates a user-friendly JavaScript-based visual tool that allows users to design customized workflows even for those without a technical background. With the inventory management system, reagents, laboratory glassware and consumables can be easily added through their barcodes and minimum stock levels can be controlled to avoid shortages of essential laboratory supplies. QTREDS provides a system for privileges management and authorizations to create different user roles, each with a well-defined access profile.ConclusionsTracking and monitoring all the phases of the laboratory activities can help to identify and troubleshoot problems more quickly, reducing the risk of process failures and their related costs. QTREDS was designed to address the specific needs of the CSGP laboratory, where it has been successfully used for over a year, but thanks to its flexibility it can be easily adapted to other "omics" laboratories. The software is freely available for academic users from http://qtreds.crs4.it.

Automating the 2G superconducting rock magnetometer for single‐solenoid alternating field demagnetization

We have automated a 2G Enterprises superconducting magnetometer to measure and demagnetize standard paleomagnetic samples. After loading a sample and setting the desired demagnetization steps, the operation is performed without further operator attention. Each of a sample's three axes is measured in both directions multiple times. A single solenoid performs three‐axis static demagnetization by rotating the specimen 120° about an oblique axis to each orthogonal position. This eliminates potential errors resulting from differences between the fields generated when using two orthogonal coils with different geometry. Each sample is handled only once, minimizing angular alignment errors. For initial sample moments 10–100 times the holder moment (i.e., natural remanent magnetizations greater than 10−3 A/m for standard size samples), very high quality AF demagnetization results can be obtained. The procedure for a complete, 10‐ to 20‐step alternating field (AF) demagnetization takes between 20 and 70 min, depending on the sample's moment. This automated system is complemented by a custom program that controls all system elements, including the magnetometer, AF demagnetizer, and sample handler that shuttles the sample between the two and also rotates the sample to the measurement positions. In addition, the controlling software includes tools for (1) sample parameter input and instant results recalculation upon parameter adjustment, (2) real‐time results visualization, (3) integrated Sun compass correction software, and (4) several demagnetization routines optimized for different magnitudes of magnetization. The software uses a very general and flexible, XML‐based file structure capable of storing an entire field study in one hierarchical file format, with levels for locality, site, sample, and demagnetization step. It serves as an electronic field notebook for recording many more parameters and comments than those strictly needed to measure the direction of the core.

Automated sample exchange and tracking system for neutron research at cryogenic temperatures

An automated system for sample exchange and tracking in a cryogenic environment and under remote computer control was developed. Up to 24 sample "cans" per cycle can be inserted and retrieved in a programed sequence. A video camera acquires a unique identification marked on the sample can to provide a record of the sequence. All operations are coordinated via a LABVIEW program that can be operated locally or over a network. The samples are contained in vanadium cans of 6-10 mm in diameter and equipped with a hermetically sealed lid that interfaces with the sample handler. The system uses a closed-cycle refrigerator (CCR) for cooling. The sample was delivered to a precooling location that was at a temperature of approximately 25 K, after several minutes, it was moved onto a "landing pad" at approximately 10 K that locates the sample in the probe beam. After the sample was released onto the landing pad, the sample handler was retracted. Reading the sample identification and the exchange operation takes approximately 2 min. The time to cool the sample from ambient temperature to approximately 10 K was approximately 7 min including precooling time. The cooling time increases to approximately 12 min if precooling is not used. Small differences in cooling rate were observed between sample materials and for different sample can sizes. Filling the sample well and the sample can with low pressure helium is essential to provide heat transfer and to achieve useful cooling rates. A resistive heating coil can be used to offset the refrigeration so that temperatures up to approximately 350 K can be accessed and controlled using a proportional-integral-derivative control loop. The time for the landing pad to cool to approximately 10 K after it has been heated to approximately 240 K was approximately 20 min.

Sample handler for x-ray tomographic microscopy and image-guided failure assessment

X-ray tomographic microscopy (XTM) yields a three-dimensional data model of an investigated specimen. XTM providing micrometer resolution requires synchrotron light, high resolution area detectors, and a precise sample handler. The sample handler has a height of 270 mm only, is usable for 1μm resolution, and is able to carry loading machines with a weight of up to 20 kg. This allows exposing samples to load between scans for image-guided failure assessment. This system has been used in the XTM end station of the materials science beamline of the Swiss Light Source at the Paul Scherrer Institut.

High-Throughput Microcoil NMR of Compound Libraries Using Zero-Dispersion Segmented Flow Analysis

An automated system for loading samples into a microcoil NMR probe has been developed using segmented flow analysis. This approach enhanced 2-fold the throughput of the published direct injection and flow injection methods, improved sample utilization 3-fold, and was applicable to high-field NMR facilities with long transfer lines between the sample handler and NMR magnet. Sample volumes of 2 microL (10-30 mM, approximately 10 microg) were drawn from a 96-well microtiter plate by a sample handler, then pumped to a 0.5-microL microcoil NMR probe as a queue of closely spaced "plugs" separated by an immiscible fluorocarbon fluid. Individual sample plugs were detected by their NMR signal and automatically positioned for stopped-flow data acquisition. The sample in the NMR coil could be changed within 35 s by advancing the queue. The fluorocarbon liquid wetted the wall of the Teflon transfer line, preventing the DMSO samples from contacting the capillary wall and thus reducing sample losses to below 5% after passage through the 3-m transfer line. With a wash plug of solvent between samples, sample-to-sample carryover was <1%. Significantly, the samples did not disperse into the carrier liquid during loading or during acquisitions of several days for trace analysis. For automated high-throughput analysis using a 16-second acquisition time, spectra were recorded at a rate of 1.5 min/sample and total deuterated solvent consumption was <0.5 mL (1 US dollar) per 96-well plate.

N-Deethylation and N-oxidation of etamiphylline: identification of etamiphylline- N-oxide in greyhound urine by high performance liquid chromatography–mass spectrometry

Millophyline-V ®, (etamiphylline camsylate) was administered intramuscularly to two racing greyhounds at a dose of 10 mg kg −1. Unhydrolysed pre- and post-administration urine samples were extracted using mixed mode solid phase extraction (SPE) cartridges, the basic isolates derivatised as trimethylsilyl ethers and analysed by positive ion electron ionisation gas chromatography–mass spectrometry (GC/EI+/MS). The parent drug and one metabolite, N-desethyletamiphylline, were detected in urine for up to 72 h. For semi-quantification, urine samples were extracted on-line using a Prospekt sample handler. The analytes retained on the C 2 SPE cartridge were eluted by the mobile phase directly on to the analytical high performance liquid chromatography column and analysed by positive ion atmospheric pressure chemical ionisation (LC/APCI+) MS in the multiple selective-ion recording mode. A major peak containing both ions ( m/ z) 280 and ( m/ z) 252 was observed. Full scan LC/APCI+/MS of the unknown indicated that the ion at ( m/ z) 280 was formed by the loss of an oxygen atom [ MH + → ( MH + − O)]. Samples were analysed by positive ion electrospray ionisation LC/MS on two different instruments and the unknown compound was identified as an N-oxide of the tert. nitrogen atom of the 2-(diethylamino)ethyl substituent on N 7 of the theophylline nucleus. This compound has not been reported previously either as an in vivo or in vitro metabolite of etamiphylline in any species. Thermal decomposition of the N-oxide could lead to an increase the detection period of the parent drug during routine GC/MS screening of post-competition greyhound urine samples.

Simple Medicine

Abbott Laboratories’ diagnostics division claims that the systems improve laboratory workflow. A patented feature of the machines is an automated system called the retest sample handler, which can hold up to 135 sample vials for the i2000sr, 185 for the c8000, and 335 for the ci8200. The samples, which are accessible to a three-axis carrier transport robot, can be picked up in any sequence so they can be retrieved for retesting when it is necessary. Eliminating separate rails and associated fasteners and reducing machining of large surfaces resulted in significant cost savings. In addition, the single extrusion offers improved structural strength in the given space at the lowest weight. Fewer parts minimized tolerance stackup. Electronic components in the original design included circuit boards and cable harnesses in different configurations for each module type. The final design has 18-inch-long circuit boards that can be joined to form a continuous board up to 10-feet long, without cables.

Detection of Eltenac in the Horse: Identification of Phase I Metabolites in Urine by Capillary Gas Chromatography-Mass Spectrometry and the Determination of Excretion Profile by Liquid Chromatography-Mass Spectrometry

Telzenac® (Eltenac; 0.5 mg kg−1) was administered intravenously to two thoroughbred horses. After initial alkaline saponification followed by enzymolysis of the urinary phase II conjugates, the combined unconjugated compounds and aglycones were isolated by mixed mode solid phase extraction (SPE). The acidic isolate was either methylated or silylated (trimethylsilyl ether, TMS) and analysed by positive ion electron ionisation gas chromatography-mass spectrometry (GC-EI+-MS). Eltenac and two isobaric metabolites, hydroxyeltenac (aromatic oxidation) and eltenac sulfoxide were tentatively identified. Base peaks in the EI+ spectra of underivatised, methylated and TMS derivatised eltenac are formed by an initial loss of H2O, CH3OH or (CH3)3-Si-OH respectively, followed by successive losses of a chlorine atom and a carbonyl group. Similar fragmentation patterns were observed for the methyl and TMS derivatives of the two metabolites. Triamcinolone acetonide was used as the internal marker for the semi-quantification of eltenac. Selected samples were base-hydrolysed and extracted on-line on a C2 SPE column using a Prospekt sample handler. The retained analytes were eluted directly on to an analytical LC column and analysed by high performance liquid chromatography positive ion atmospheric pressure chemical ionisation MS in the selective ion recording mode. Most of the drug was excreted in less than 24 h. However it could still be detected in urine by full-scan GC-EI+-MS for over 96 h.

Magnetic Resonance Diagnostics: A New Technology for High-Throughput Clinical Diagnostics

Magnetic resonance diagnostics (MRD) uses automated, high-throughput nuclear magnetic resonance (NMR) spectroscopy for the rapid identification and quantification of small-molecule metabolites in biofluid mixtures (blood, urine, saliva, cerebrospinal fluid, and others). Specifically, MRD involves using a high-field (400 MHz) NMR instrument equipped with a small-volume flow probe and robotic sample handler to rapidly load biofluid samples and to collect their 1H NMR spectra. Spectral deconvolution software automatically assigns individual peaks to particular compounds and calculates concentrations from peak areas. MRD uses the principle of chemical shift separation to physically separate and identify individual compounds directly from 1H NMR spectra, thus avoiding chromatographic separation steps (e.g., HPLC, gas chromatography, and capillary electrophoresis). MRD is useful for rapid (<2 min per sample) qualitative and quantitative assessment of small-molecule metabolites. NMR spectroscopy is not new to the field of clinical chemistry. Indeed several important applications have already been demonstrated in the area of diagnosis and therapeutic monitoring of metabolic disorders (1)(2)(3)(4), in toxicologic and renal testing (5)(6), and in the profiling of blood lipoproteins and cholesterol (7). An emerging approach to enable high-throughput in vivo toxicology is called metabonomics, which uses high-resolution NMR to rapidly evaluate the metabolic status of an animal (8)(9). A key limitation to all of these NMR approaches is that they depend on manual sample handling and/or manual (i.e., expert) spectral analysis. This has made most NMR approaches to clinical analyses far too slow or too costly for routine chemical profiling or high-throughput screening. Because MRD is fully automated (sample handling, spectral collection, and spectral analysis are all handled by robots or computers), this technique offers the potential for high-throughput, comprehensive, and inexpensive chemical analysis of a wide range of biofluid samples. To demonstrate the potential …

Use of the Cell-Dyn 3500 in a Reference Laboratory

The Cell-Dyn 3500 (Abbott Laboratories, Abbott Park, III) is a high-throughput hematology analyzer that includes laser technology, dual white cell analysis, and a closed-tube autosampler that can hold up to 100 blood samples at a time. In this study, the Cell-Dyn 3500 was compared with the Coulter STKS (Coulter Electronics, Hialeah, Fla) for its use in a reference laboratory setting. Among 367 samples tested in parallel, the Cell-Dyn 3500 did not differ statistically from the STKS. The STKS required 29 (8%) of the samples to have manual microscopic analysis; the Cell-Dyn 3500 required 32 (9%). The automated sample handler on the Cell-Dyn 3500 worked well. Instruments were compared statistically for several parameters and evaluated for consistency in analysis of aged blood samples. Blood samples tested through 96 hours on the Cell-Dyn 3500 showed stability of white cell counts through 48 hours; stability of red cell counts through 72 hours; and stability of hemoglobin and hematocrit through 96 hours. The Cell-Dyn 3500 performance was found to be acceptable for a reference laboratory setting.

Automated HPLC assay of fluoxetine and norfluoxetine in serum

This automated assay determines the concentration of the antidepressant fluoxetine (Prozac) and its active metabolite norfluoxetine in serum by reversed-phase HPLC with spectrophotometric detection. Extraction, injection, and quantification are performed by the Gilson Aspec automated sample handler. The patient's specimen, with added protriptyline as internal standard, is extracted with solid-phase and liquid-liquid methods. Separation is conducted isocratically on a 5-microns (particle size) Supelcosil LC-8-DB reversed-phase column with a triethylamine acetate:acetonitrile mobile phase. The detection limit is 10 micrograms/L and absorbance varies linearly with concentration between 20 and 1,000 micrograms/L for both compounds. Mean recovery was 62% for fluoxetine and 70% for norfluoxetine over linear limits. Within-run and day-to-day imprecision (CV), evaluated at three concentrations (50, 200, and 500 micrograms/L), ranged from 2% to 7%. An extensive interference study of 108 drugs was conducted. Results (n = 58) by the automated method (y) correlated well with those by a manual HPLC method (x): y = 0.96x + 10.20 (r = 0.951, Sylx = 42.9) for fluoxetine, and y = 0.95x - 1.37 (r = 0.917, Sylx = 47.2) for norfluoxetine.